dsh-chat-index: DeepSeek Harness Session Prompt Index

`dsh-chat-index` is a web plugin for DeepSeek Harness (DSH) designed to address the pain point of locating questions in long conversations. Its core features include a right-side question rail (click to locate, drag to preview) and a chain panel (displays node summaries and supports subtree views of branched conversations). The plugin is purely front-end based and easy to install. Through a visual index, users can quickly jump to and highlight questions, significantly improving the efficiency of reviewing multi-turn or branched conversations.